Horizontal deflection output circuit

Abstract

In a horizontal deflection output circuit in which a horizontal output transistor, a damper diode and a resonance capacitor are respectively connected in series with a horizontal deflection coil, a series circuit of a resistor and a capacitor is connected with the damper diode and a second diode is connected with the resistor. The time constant of the series circuit is so chosen that the second diode starts conducting current at the beginning of the horizontal scanning period, and therefore the horizontal deflection current flows through the second diode at the beginning of the horizontal scanning period so that the linearity of the horizontal deflection current can be prevented from degrading immediately after the beginning of the horizontal scanning period.

I claim: 
     
       1. A horizontal deflection output circuit comprising a means for causing a horizontal deflection current to flow through the horizontal deflection coil in one direction during the period from an intervening instant within the horizontal scanning period to the end of said horizontal scanning period;   a resonance capacitor for generating a resonance current in cooperation with said horizontal deflection coil during the horizontal flyback period; and   a damper diode for bypassing said resonance current and for causing said resonance current to flow through said horizontal deflection coil in the direction opposite to said one direction from the instant corresponding to the end of the rise time of said horizontal deflection current, after the start of the horizontal scanning period, till said intervening instant, wherein said horizontal deflection output circuit is provided with a damping means which assumes a low impedance and serves as a bypass for said resonance current during at least a portion of said rise time, and has no influence on the current through said horizontal deflection coil during any period other than said rise time.   
     
     
       2. A horizontal deflection output circuit as claimed in claim 1, wherein said damping means comprises a series circuit of a resistor and capacitor, said series circuit being connected in parallel with said damper diode, and an auxiliary damper diode connected in parallel with said resistor in such a manner that the conducting direction of said auxiliary damper diode coincides with that of said damper diode. 
     
     
       3. A horizontal deflection output circuit as claimed in claim 1, wherein said damping means is a series circuit of a zener diode and a capacitor, said series circuit being connected in parallel with said damper diode. 
     
     
       4. In a horizontal deflection output circuit having: a horizontal deflection coil;   switching means having a unidirectional conductive path coupled in parallel to said horizontal deflection coil and a control terminal supplied with a control signal of a horizontal frequency for controlling conductive and non-conductive states of said unidirectional path, and   a damper diode coupled in parallel to said horizontal deflection coil with a conductive polarity opposite to that of said unidirectional conductive path and unavoidably having a rise time to become conductive at the beginning of a horizontal scanning period, the improvement comprising;   damping means coupled in parallel to said damper diode, said damping means being rendered conductive during at least a portion of said rise time and otherwise rendered non-conductive.   
     
     
       5. In a horizontal deflection output circuit having: a means for causing a horizontal deflection current to flow through the horizontal deflection coil in one direction during the period from an intervening instant within the horizontal scanning period to the end of said horizontal scanning period;   a resonance capacitor for generating a resonance current in cooperation with said horizontal deflection coil during the horizontal flyback period; and   a damper diode for bypassing said resonance current and for causing said resonance current to flow through said horizontal deflection coil in the direction opposite to said one direction from the instant corresponding to the end of the rise time of said horizontal defection current, after the start of the horizontal scanning period, till said intervening instant, the improvement comprising:   damping means coupled in parallel to said damper diode and presenting a low impedance to serve as a bypass for said resonance current during at least a portion of the early stage of said rise time, and a high impedance during any period other than said low impedance period.